1. Technical Field
The technical field relates to a lubricating device of a gear apparatus for a vehicle to lubricate a low-rotation-side gear and a high-rotation-side gear meshing with the low-rotation-side gear.
2. Description of Related Art
There have been known lubricating devices of gear apparatuses for vehicles to lubricate low-rotation-side gears and high-rotation-side gears meshing with the low-rotation-side gears. In such gear apparatuses for the vehicles, in order to secure durability of gear pairs of the low-rotation-side gears and the high-rotation-side gears, it is required to securely perform both formation of oil films on tooth surfaces of the low-rotation-side gears and the high-rotation-side gears and cooling of the tooth surfaces thereof. A lubricating device of a gear apparatus for a vehicle described in Japanese Patent Application Publication No. 10-122310 includes: lubricating oil supply nozzles to directly supply a lubricating oil to a meshing position between a large gear as a low-rotation-side gear and a small gear as a high-rotation-side gear; and a lubricating oil supply pipe to supply an oil from an oil pump to the lubricating oil supply nozzles, and this lubricating device is configured to directly supply oil mist to the above meshing part.
FIG. 8 is a schematic view explaining one example of a lubricating device of a gear apparatus for a vehicle of related art as described in JP 10-122310 A. FIG. 9 is a view explaining one example of a lubricating method in the lubricating device of the gear apparatus for the vehicle of the related art. Arrows in FIG. 9 indicate that a tooth surface cooling method of a low-rotation-side gear (low-speed rotation-side gear) is a forced lubrication that is the same as that of an oil film forming method, and a tooth surface cooling method of a high-rotation-side gear (high-speed rotation-side gear) is a forced lubrication that is the same as that of the oil film forming method. In FIG. 8, a lubricating device 110 of a gear apparatus for a vehicle of the related art includes an oil supply pipe 112 above a low-rotation-side gear (low-speed rotation-side gear) 114 provided to an output shaft, and supplies the lubricating oil directly to a meshing position 118 between a high-rotation-side gear (high-speed rotation-side gear) 116 provided to an input shaft and the low-rotation-side gear 114. Here, to supply the lubricating oil directly to gears so as to lubricate tooth surfaces of these gears is referred to as a forced lubrication. As shown in FIG. 9, through this forced lubrication, formation of the oil film on the tooth surfaces of the low-rotation-side gear 114 and the high-rotation-side gear 116, and cooling of the tooth surfaces thereof are both secured.